A 36-year-old woman is brought to the emergency department with sudden-onset right side weakness and speech difficulty. During the last 3 weeks, the patient has experienced progressive fatigue, malaise, and low-grade fevers. Despite the symptoms, she did not seek medical attention and did not take any medications. She had a dental extraction 5 weeks ago, which was uncomplicated. The patient has never previously been significantly ill or hospitalized. She works as a receptionist at a legal firm and has never traveled outside the United States. She does not use tobacco, alcohol, or illicit drugs. The patient is admitted to the hospital, but despite adequate resuscitative measures, she dies 2 hours later. Gross autopsy shows large, friable irregular masses attached to the atrial surface of a valve. Which of the following underlying conditions most likely predisposed this patient to developing these cardiac changes?

Question

A 36-year-old woman is brought to the emergency department with sudden-onset right side weakness and speech difficulty.  During the last 3 weeks, the patient has experienced progressive fatigue, malaise, and low-grade fevers.  Despite the symptoms, she did not seek medical attention and did not take any medications.  She had a dental extraction 5 weeks ago, which was uncomplicated.  The patient has never previously been significantly ill or hospitalized.  She works as a receptionist at a legal firm and has never traveled outside the United States.  She does not use tobacco, alcohol, or illicit drugs.  The patient is admitted to the hospital, but despite adequate resuscitative measures, she dies 2 hours later.  Gross autopsy shows large, friable irregular masses attached to the atrial surface of a valve.  Which of the following underlying conditions most likely predisposed this patient to developing these cardiac changes?

Quizplus · Accepted Answer

This patient had subacute infective endocarditis (IE) complicated by an embolic stroke. The large, friable irregular masses seen on autopsy are most likely vegetations and are the most probable source of this patient's left middle cerebral artery embolus (eg, right-sided weakness, speech difficulty). The mitral valve is the valve most frequently affected by IE. Mitral valve prolapse (MVP) is the most common underlying valvular disease predisposing to the development of IE in developed countries, particularly when it is associated with coexistent mitral regurgitation. Microscopic deposits of platelets and fibrin occur spontaneously in individuals with valvular disease secondary to endocardial injury from turbulent blood flow. These deposits then become colonized by microorganisms (eg, viridans streptococci) during episodes of bacteremia (eg, following dental extraction). In developing countries, the most common acquired heart disease leading to IE development is rheumatic heart disease (RHD). RHD is a late (10-20 years) complication of acute rheumatic fever (eg, migratory arthritis, carditis/valvulitis, erythema marginatum). RHD was historically considered a frequent predisposing factor for IE; however, MVP, valvular sclerosis, and mechanical valves are now more common causes in developed nations due to the recognition and treatment of group A streptococcal pharyngitis. (Choice A) Congenital heart lesions that predispose to increased risk of IE include bicuspid aortic valve, ventricular septal defects, patent ductus arteriosus, and unrepaired tetralogy of Fallot. Isolated atrial septal defects are not commonly associated with an increased risk of IE, likely due to the low-pressure differential between the atria and the absence of high-velocity intracardiac flow jets that can damage the endocardium. (Choice B) Coronary heart disease can cause ischemic papillary muscle dysfunction with resultant mitral regurgitation. However, the clinical presentation and autopsy findings in this patient are most consistent with MVP and IE. (Choice C) IE is a rare complication of hypertrophic cardiomyopathy and is almost always seen in patients with outflow obstruction. Hypertrophic cardiomyopathy is characterized by asymmetric ventricular hypertrophy leading to reduced left ventricular cavity size. (Choice D) Mitral annular calcification refers to degeneration and progressive calcium deposition involving the fibrous annulus of the mitral valve. Mitral annular calcification is usually seen in older adults (age >60), and the annulus is not a common location for IE. Educational objective: Mitral valve prolapse with regurgitation is the most common predisposing condition for native valve infective endocarditis (IE) in developed nations. Rheumatic heart disease remains a frequent cause of IE in developing nations. __________ References: Incidence and predictors of infective endocarditis in mitral valve prolapse: a population-based study. (http://www.ncbi.nlm.nih.gov/pubmed/26856780) The worldwide epidemiology of acute rheumatic fever and rheumatic heart disease. (http://www.ncbi.nlm.nih.gov/pubmed/21386976)

A 36-Year-Old Woman Is Brought to the Emergency Department with Sudden-Onset